52 



TIL-iA'SFORMATIOXS OF INSECTS. 



breathe very slowly. The energy and the rapidity of the respi- 

 ratory efforts increase during any agitation. An insect may be 

 crawling over the leaves, or upon the ground, with very little air 



THE RESPIRATORY APPARATUS OF THE BEE. (Magnified.) 



in its tracheae. Its body is heavy, and it could not fly unless it 

 contained more air ; so the insect lifts up its wings, and makes 

 a few energetic movements of its abdomen, in order to fill the 

 vesicles and tracheae to the utmost, and sails away. 



The long voyages of immense columns of locusts arc welt 



